Means for controlling feeding mechanisms



April 21, 1925.

1,535,080 H K. SPENCER MEANS FOR CONTROLLING FEEDING MECHANISMS 5Sheets-Sheet 1 Filed July so, 1921 .Henryl jispe?u;er

April 21, 1925. 1,535,080

H. K. SPENCER MEANS FOR CONTROLLING FEEDING MECHANISMS File July 1921 5Sheets-Sheet 2 lnveni'ow f Z@ Z Hera-311'. S o 021L 62, /5/ y a April21, 1925. 1,535,080

H. 'K. SPENCER MEANS FOR CONTROLLING FEEDING MECHANISMS File July 0,1921 5 Sheets-Sheet 4 177/276311770? I Henry K.S;aen0en April 21, 1925.v

" H. K. SPENCER MEANS FOR CONTROLLING FEEDING MECHANISMS 5 Sheets-Sheet5 Inveniow:

HenqyILSpenc-er, 27y Co r Patented Apr. 21, 1925.

UNITED STATES arent HENRY K. SPENCER, OF WATERTOWN, MASSACHUSETTS,ASSIGN'OR TO THE BLANCH- ARD MACHINE COMPANY, OF CAMBRIDGE,MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS.

MEANS FOR CONTROLLING FEEDING MECHANISMS.

Application filed July 30, 1921. Serial No. 488,747.

To all whom it may concern:

Be it known that I, HENRY K. SPENCER, a citizen of the United States,anda resident of VVatertown, in the county of Middlesex and State ofMassachusetts, have invented an Improvement in Means for ControllingFeeding Mechanisms, of which the following description, in connectionwith the accompanying drawings, is a specification, .like characters onthe drawings representing like parts.

This invention relates to means for controlling a working function of amachine, and is more especially concerned with a feed control for metalworking machines such as surface-grinders. The invention will be bestunderstood by reference tothe following description'when taken inconnection with the accompanying drawings of one specific embodiment ofthe means by which the method may be carried out, while its scope willbe more particnarly pointed out in the appended claims.

In the drawings,

Fig. 1 is a skeletonized elevationpartly in section of a portion of agrinding machine equipped with a feed control exemplifying theinvention, some parts of the machine being slightly rearranged ascompared with their arrangement in practice, this being done forconvenience and clearness of dis closure; 7

Fig. 2 is a diagram of-tlie electrical connections of the feed control;

Fig. 3 is a plan of that portion of the feed control which directlycooperates with the work. the same being shown on a lunch enlargedscale;

Fig. 4-. is adetail elevation of the work engaging shoe and its carrieras viewed in the direction of the arrow 4; in Fig. 3;

Fig. 5 is a detail elevation of some of the parts shown in". Fig. 3viewed in the dircction of the arrow 5; i

Fig. 6 is a detail elevation of sonie of the parts shown in Fig. 3viewed in the direction of the arrow 6;

Fig. 7 is a detail plan on an enlarged scale of one of the electricalcontacts shown in Fig. 3;

Fig. 8 is a detail plan section illustrating the other electricalcontact shown in Fig. 3:

Fig. 9 is a detail sectional view on line 9-9 of Fig. 3;

Fig. 10 is an elevation on an enlarged scale of some of the parts shownat the upper right-hand portion of Fig. 1;

Fig. 11 is a plan of the parts shown in Fig. 10;

Fig. 12 is a detail sectional view on line 1212 of Fig. 11; and

Fig. 13 is a detail sectional view on line 13-13 of Fig. 10.

Referring to the drawings and to the embodiment of the invention whichis selected for exemplification, there is shown a portion of a metalworking tool of the class represented by U. S. Letters Patent No.1,182,861. dated May 9, 1916, commercially known as the Blanchardvertical surface grinder. The general characteristics of the grindingmachine will first be described, followed by a description of the feedcontrol.

Referring to Fig. 1, the machine comprises a suitable. work support,herein a rotary chuck or turn table 15, which in practice is usuallymagnetic the better to enable it tohold small pieces of work with outthe necessity of employing-clamps. The chuck is mounted to rotate abouta vertical axis and is provided with driving mechanism, including a ringgear 17 meshing with a driving pinion 19. the latter being secured to'a.shaft 21, to which is also secured a mit're gear 23 which meshes with amitre gear 25. The latter is secured to and driven by a horizontal shaft27, which in practice may be driven at various speeds through the use ofa change speed mechanism, a por tion only of which is shown herein, thesame comprising a spur gear 29 secured to the. shaft 27 and meshing witha spur gear 31 secured to and driven by a main driv ng shaft 33' havinga driving pulley 35.

screw 51, to which is secured a bevel gear 53* meshing with a-beveledpinion 55, the latter being secured to a horizontal shaft 57, to whichis also secured a mitre gear 59 which meshes with a mitre gear 61. Thelatter is secured to a shaft 63 to which is also-secured a. ratchet feedwheel (iii-cooperating with a spring pressed pawl 67. A pawl carrier 69is in the form of a lever mounted to rockabout' the axis of the shaft 63and is swung to and fro by a link 71, provided with a slot 73 whichreceives a crank pin .75 carried by a crank 77, the latter being securedto a shaft 79. Also secured to this shaft is a worm gear 81 meshing witha worm 83 which is secured to a vertical shaft 8,5,to the lower end ofwhich is also secured a mitre gear 87 meshing with a mitre gear 89secured to and driven by the shaft 27.

The operation of the machine as thus far described will nowbe described.The chuck is rotated in the direction of the arrow A in Figs. 1 and 3and the abrasive wheel 37 is preferably rotated in the direction of thearrow B. Work pieces 91 are placed upon the face of the chuck and therotation of-the latter brings them successively befneath the abrasivewheel, whose action reduces the thickness of the pieces. The amount ofmaterial which is taken off is dependent upon the vertical position ofthe abrasive wheel and is determined by the feeding mechanism. As thegrinding operation proceeds the abrasive wheel is gradually loweredthrough the action of the feeding mechanism in the following manner. Thepower which is transmitted to the worm 83 rotates the latter and causesthe ro-v tation of the worm gear 81, the shaft 79 and the crank arm 77.The crank pin 75 engages the upper end of the slot 73 and moves the link71 in an upward direction, thus giving the pawl carrier 69 and pawl 67an upward stroke which causes the ratchet fee-d wheel to beturned anamount corresponding to such stroke. When the crank pin passes beyondits uppermost position, and starts to travel in a downward direction thelink, pawl carrier and pawl will follow by the action of gravity untiltheir downward movement is limited by a stop 93. The rotation ofthe feedwheel which has thus taken place is transmitted through the mitre gears61 and 59, shaft 67, bevel pinion 55 and bevel gear 53 to the feedscrew. 51 which, being held against movement in a vertical direction,imparts a vertical movement to the nut 49 and wheel head 47. The amountof feed is determined by the position of the stop 93 which of coursedetermines the stroke of the feed pawl.

The means for controlling the position of the stop will now bedescribed, reference being had first to Figs. 10 to 13, inclusive. Thestop. 93 is suitably mounted for movement into and out of the path of alug 95 carried by the pawl carrier 69, and in the present example thisis conveniently accomplished by making the stop in the form of a platewhich is disposed in a general horizontal position and is mounted toslide in a general horizontal direction in and out with reference to thepawl carrier. The plate is mounted upon a guide 97, herein formed as.

a part of a supporting bracket 99, which is preferably mounted foradjustment about the axis of the pawl carrier. Referring to Fig. 13which shows this construction inplan section, the adjustable bracket 99constitutes a slide having surfaces 101 guided by an arc-shaped guide103, whose center is the axis about which the pawl carrier swings. Thisguide is herein formed on a plate 105 which is fixedly secured as byscrews 107 to the framework 109 of the machine (see Fig. 11). The plate105 is herein provided with a lug 111 constitutingv a pointer providedwith the reference mark 113 to assist the operator in'setting the feedwheel. Likewise the guide 103 is provided with suitable graduations 115cooperating with the lug 95 to assist the operator in settingthe'bracket 99. Referring to Fig. 13, the latter is normally held in theselected position of adjustment by a clamping screw 117 having screwthreaded engagement with the bracket as at 119, and adapted to engagethe guide 103 thereby to clamp the bracket thereto.

\Vhen, however, the stop 93 isplaced in its forward position representedin Fig. 10, it is in the path of the lug 95 carried by the pawl carrier69 and thus limits'the downward swing of the latter. the stop isWithdrawn rearwardly 01; toward the right in Fig. 10, the downwardstroke of the pawl carrier is limited only by its engagement with theguide 97 on which the stop 93 slides. When this takes place the pawlcarrier has a greater stroke and imparts to the abrasive wheel acorrespondingly greater amount of feeding movement. If desired I mayemploy an auxiliary stop 93-similar to and superposed uponthe stop 93.lVhen the auxiliary ,stop is brought forward into the path of the lugand the pawl carrier, the stroke of the latter is naturally limited to astill greater extent. In the present example the auxiliary stop .lV-hen,however, 1

Inc

test ed is adjustably positioned upon the main stop by providing theformer with two holes 121 and 123, either of which is adapted to receivea pin 125 which is also received in a hole 127 provided in the mainstop. A screw-129 threaded into the guide 97 is received in slots 131and 131 provided in the stops 93 and 93 respectively. When it is desiredto bring the auxiliary stop 93 forward into alignment with the main stop93 this may be accomplished by simply lifting the auxiliary stop fromits engagement with the pin 125 and sliding the same forward until thehole 123 comes into registration with said pin and then dropping theauxiliary stop so that the pin enters said hole.

The movement of the stop into and out of the path. of'the pawl carriermay be controlled by the condition of the work, and the reduction of thethickness of the latter to the predetermined dimension may be utilizedin some suitable way to bring the stop forward into position where itwill modify or altogether stop the action of the pawl carrier. 4

In the present example, the position of the stop is controlled by alever 133 which carries the pin 125 and is fulcrumed on a pivot 135 gnthe bracket 99. The latter is provided with a slot 137 (see Fig. 12) inSecured which the pin plays to and fro. to the lever is an. armature 139cooperating with the pole pieces 141 of a magnet 143 mounted on thebracket 99.

A suitably arranged spring 145, the load of which may be adjusted by anabutment 147 carried by an adjusting screw 149, constantly tends to movethe armature away from the magnet and to carry the stop into the path ofthe pawl carrier. "When, however, the magnet is energized it attractsthe armature 139and overcomes the spring 145, thus causing the stop tobe withdrawn from the path of the pawl carrier. The making and breakingof the magnet circuit may be accomplished by suitable means, now to bedescribed, controlled by the condition of the work, reference being hadfirst to Figs. 3 and 4.

A suitably shaped follower or shoe 151 is adapted to ride upon the uppersurface of the work which travels. relatively thereto, and thefrictional resistance to such movement is utilized to control the feed.To this end the shoe is mounted upon a carrier 153 which is movable in ageneral direction lengthwise of the travel of the work. Referring toFig. 9, in the present example the shoe is secured to the carrier byproviding the latter with a slot 15 5 which receives the shoe, thelatter being clamped in place by one or more, herein a plurality, of setscrews 157. These screws may be caused to urge the shoe into the slot byproviding each screw with a conical point 159 received in a conicalrecess 161 provided in the shoe and so placed that the conical point ofthe screw is offset. in an upward direction from the axis of depression.It follows that the inward movement of the screw is accompanied byupward movement of the shoe in the slot. The shoe is therefore graduallypositioned and firmly held in place in itscarrier.

Referring now to Fig. 6, in the present embodiment the carrier 153 isformed as a part of a lever 163 which is fulcrumed on a pivotalmounting, as, for example, a pair of conically shaped pivots 165, whichis mounted for axial adjustment. in lugs 167 formed on a bracket 169.The latter in turn is received in a groove 171 provided in a collar 173in which it is fixedly secured by screws 175.

The collar 173 is mounted for vertical ad justment upon a suitable fixedsupport,

herein a post 177. In the present example,

this is accomplished by the use of an adjusting nut 179 having screwthreaded engagement with the post and serving as a stop against whichthe collar 173 is urged by a spring 181 interposed between the bottom ofthe collar and an abutment 183 at the bottom of the post. The collar hassplined connection with the post, as by a key 185 (see Fig. 3). Itfollows that rotation of the adjusting nut 179 is accompanied byvertical movement of thecollar 173. The latter is herein split as at 186and is provided with a clamping screw 187, by means of which it may becaused to grip the post 1'77 more or less firmly as circumstances mayrequire. If desired, the adjusting nut may be provided with suitablegraduations 189 and the collar 17 3 with the cooperating reference mark191, although these are not at all essential as the adjustment will beusually accomplished by trial of the shoe against a test piece of knownthickness placed upon the chuck. The shoe will be adjusted until it justtouches againstthe top of the test piece without suflicient frictionalresistance to cause it to be dragged along during the rotation of thechuck.

Referring to Fig. 3, movement of the shoe in the direction of travel ofthe work is resisted by a suitable spring 193, the resistance of whichmay be varied by an adjustable abutment 195, herein carried by anadjusting screw 197 having screw threaded engagement with the lever 163.When in the operationof the machine a work piece. having passed beneaththe abrasive wheel and still being of greater thickness than the testpiece by which the shoe is adjusted, passes beneath the latter thefrictional resistance overcomes the resistance presented by the spring193 and causes the lever 163 to be rocked in a clockwise direction, asviewed contact member 199- is provided with a binding post 209 having,anut 211 by means of which a terminal lead wire 213 may be securedthereto.

Referring again to Fig. -3, the contact 201 is preferably yieldinglymounted,

as by being secured to one arm of a U-shaped I whose other arm issecured to a bracket 217, which in turn is secured tothe collar 173.'Thus in the operation of the machine when the contact 199 brings upagainst the contact 201, the latter yields to an extent limited by 2.preferably adjustable stop, herein a screw 219 threaded into the bracket217. The latter is provided with a binding post 221 having a nut 223 bymeans of which the terminal of a lead wire 225 may be secured thereto.

Referring now to Fig. 2.21s a diagrammatic illustration of theelectrical circuit, there is suitably interposed in the latter a sourceof current such as a battery 227. lVhen, now, the circuit is closed bythe contact 199 bringing up against the contact 201, the magnet 143 isenergized and attracts the armature 139, thus'causing the spring 215,

l movable stop 93 to be withdrawn from the path of the pawl carrier.

This condition will continue until the abrasive wheel has removedsuflicient stock from the 7 work pieces to reduce their thickness to thetest pieces which are employed in setting the shoe, whereupon thefrictional resistance heretofore tending to drag the latter alongno'longer exists and the spring 193 asserts itself and swings the lever163 to its normal position, thereby moving the contact 199 away from thecontact 201 and breaking the circuit. whereupon the feeding mechanismeither reduces or altogether stops 'the' feed of the abrasive wheeltoward the work.

Having thus described one embodiment of the invention but withoutlimiting myself thereto, what I claim and desire by Letters Patent tosecure is:

1. In a machine for reducing a body by the removal of materialtherefrom, the combination of a reducing tool, means to cause a relativetravel of said tool and the material in the direction of the surface ofsaid body from which the material is removed,

means to cause. a relative feedof said tooland the material in adirection transverse to said surface, a follower adapted to rest againstsaid surface, and means for utilizing the frictional resistance torelative movement of said follower and said surface of said body in thefirst-named direction to control said feed.

2. In a machine for reducing a body by the removal of materialtherefrom, the combination of a shoe resting against said body, andmeans for utilizing the frictional resistance to the relative movementof the shoe and said body to control the operation of said machine.

3. The combination with a machine having a tool for removing materialfrom a travelling work surface, of a shoe resting againstsaid surface,and means for utilizing frictional resistance to the relative movementof the shoe and work surface to control the amount of material removedfrom said surface.

4. In a feeding mechanism, the combination of feeding means having apositive movement in one direction and a non-positive movement in theoppositedirection, and means movable into and out of the path of saidfeeding means in its non-positive movement.

5. In a feeding mechanism, the combination of feeding means comprisingdriving and driven parts, said driving part having a to-and-fro movementand said driven part havifigan intermittent movement in one di rection,means for imparting to said driv-. ing part a positive movement inone-direction while permitting a non-positive movement in the oppositedirection, and means movable into and out of the path of said drivingpart in its non-positive movement.

6. In a feeding mechanism, the combination of feeding means comprisingdriving and driven parts, said driving part having a to-and-fro movementand said driven part having an intermittent movement in one direction,means for imparting to said driving .part a driving movement in one,direction and permitting a non-driving return movement, and meansmovable into andout of the path of said driving part in its non-drivingreturn movement.

7. In a feeding mechanism. the combination of feeding means comprising aratchet wheel, a pawl and apawl carrier, means for imparting to saidpawlcarrier 2. driving 1 movement in the direction to cause said pawl torotate said ratchet wheel, and to permit an idle return movement of saidpawl carrier, and means movable into and out of the path of said pawlcarrier in the return movement. y

8. Ina machine of the class described, the combination of a support forthe work, a tool for reducing the work, means to cause a relative travelof the work and tool, means to cause a relatii e feeding of. said tooland work in a direction transverse to the first- ,mentioned travel, ashoe adapted to ride on the worksurface, a mounting on which said shoe15 mounted for. movement lengthwise lltl of the first-mentionedtravel,means to cause said shoe to rest upon the work and to be carriedby its frictional engagement therewith in the direction of the travel ofthe work,yielding means tending to carry said shoe in the oppositedirection, and means controlled by movement of said shoe to control therelative feeding movement of said tool and work.

9. The combination of a tool, a worksupport, a follower adapted to restagainst the work on which said toolis operating, means to causearelative transversing movement of said work-support and said tool andfollower to cause said tool and shoe to traverse the work surface, andmeans for utilizing the frictional resistance to such movement tocontrol the operation of said tool.

10. The combination of a tool, a worksupport, a follower adapted to restagainst the work on which said tool is operating, means to cause arelative traversing movement of said work-support and said tool andfollower to cause said tool and shoe to traverse the work surface, meansto cause a relative feeding movement of said worksupport and tooltransversely of said surface, and means for utilizing the frictionalresistance to said relative traversing movement to control said feedingmovement.

11. The combination of a tool, a follower adapted to rest against thework on which said tool is operating, means to cause a relativetraversing movement of said follower and work, and means for utilizingthe frictional resistance to such movement to control the operation ofsaid tool.

' '12. In a machine for removing material from work, the combination ofa follower adapted to rest against the surface from which material isremoved, means to cause relative traversing movement of said followerand work, and means for utilizing the frictional resistance to suchmovement to control the amount of material removed. 13. In a machine forremoving material from work, the combination of a tool for.

removing material, a follower adapted to rest against the surface fromwhich the material is removed, means to cause the work to be presentedfirst to said tool and then to said follower, and means for utilizingthe frictional resistance to relative travcrsing movement of said workand follower to control the amount of material removed.

14. In a machine for removing material from-work, a tool for removingmaterial, means for relatively feeding said tool and work, one towardthe other, a follower adapted to rest against the surface from which thematerial is removed, means to cause the work to be presented first'tosaid tool and then to said follower, and means lea for utilizing thefrictional resistance to work, one toward. the other, a follower.

adapted to rest against the surface from which the material is removed,means to cause the work tobe presented first to said tool and then tosaid follower, and means to cause frictional resistance to relativetraversing movement of said'work and follower to be accompanied byoperation of said feeding means and to cause cessation of suchresistance to be accompanied by modification of the feeding movement.

16. The combination of a tool, a follower adapted to rest against thework on which said tool is opera-ting,,means to cause a relativetraversing movement of said fol lower and work, yielding means tendingto cause said follower to move in a backward direction with relation tosaid movement, and means rendered effective by frictional resistancetosuch traversing movement to overcome said yielding means and to feedsaid work and tool, one toward the other, and to cause cessation of saidfrictional resistance to be accompanied by said yieldifng meansasserting itself to modify such eed.

17. In a machine for removing material from work, the combination of atool,for

removing the material, a follower adapted to rest against the work onwhich said tool is operating, means to predetermine the position of saidfollower toward and from the work surface and to be carried forward byfrictional resistance therewith, yielding means to carry said followerbackward when such frictional resistance ceases, and means controlled bythe forward and backward movement of said shoe to control the positionof said tool with reference to its capacity for removing material.

18. In a grinding machine, the combination of a grinding wheel; a gage;a worksupport to present the bodies to be ground to said grinding wheeland to said gage' in succession; normally inactive feeding means; meansincluding a normally open electrical circuit controlled by said gage forcausing engagement of said wheel with said bodies; a mounting permittingsaid gage to be dragged along by said bodies when engaged therewith andto cause the completion of said ircuit and the operation of said feedingmeans; and means for causing the restoratlon of said gage to its initialposition when not engaged by said bodies.-

19. In a machine for reducing bodies by the removal of materialtherefrom, a reducing tool; a gage; 'means to present the bodies tosaidreducing tool and to said gage in SIlCCBSSIOIl; normally inactivefeeding means for causing arelative feeding movement of said tool andsaid bodies, one toward the other; and means operated hy engagement ofsaid gage with a Work-piece to cause said feeding means to be broughtinto action and to-remain in action until there is a predeterminedthickness of said work-piece.

20. In a machine for reducing bodies by 10 the removal of materialtherefrom, a remaaoeo ducing tool; a Work support; normally inactivefeeding means for causing a relative feeding movement of said tool andwork support, one toward the other; and means operated by a Work-piecelarger than a predetermined dimension to cause said feeding means tobecome active.

In testimony whereof, I have signed my name to this specification.

HENRY K. SPENCER.

